Tissue welding and cutting apparatus and method

Abstract

A surgical apparatus and methods for severing and welding tissue, in particular blood vessels. The apparatus includes an elongated shaft having a pair of relatively movable jaws at a distal end thereof. A first heating element on one of the jaws is adapted to heat up to a first temperature and form a welded region within the tissue, while a second heating element on one of the jaws is adapted to heat up to a second temperature and sever the tissue within the welded region. The first and second heating elements may be provided on the same or opposite jaws. A control handle provided on the proximal end of the elongated shaft includes controls for opening and closing the jaws, and may include an actuator for sending current through the first and second heating elements. The first and second heating elements may be electrically connected in series, and the first heating element may be bifurcated such that it conducts about one half of the current as the second heating element. A force-limiting mechanism provided either within the control handle, in the elongated shaft, or at the jaws limits the pressure applied to the tissue by the jaws to ensure that the tissue is severed and the ends effectively welded within a short amount of time.

What is claimed is: 
     
       1. A surgical apparatus for welding and severing tissue comprising:
 an elongated shaft; 
 a first jaw and a second jaw, wherein the second jaw is relatively movable with respect to the first jaw, wherein the first jaw and the second jaw extend from a distal end of the shaft and each of the first jaw and the second jaw comprises a jaw-facing surface; 
 a first heating assembly configured to weld tissue, sever tissue, or both weld and sever tissue, wherein the first heating assembly is a component of one jaw of the first and second jaws; and 
 a second heating assembly configured to spot weld tissue, wherein the second heating assembly is a component of the same jaw as the first heating assembly; and 
 a control assembly operably connected to activate the first heating assembly and the second heating assembly. 
 
     
     
       2. The surgical apparatus of  claim 1 , wherein the first heating assembly includes a heating element actuatable by the control assembly to generate heat for welding tissue, severing tissue, or welding and severing tissue. 
     
     
       3. The surgical apparatus of  claim 2 , wherein the heating element is disposed, at least in part, on the jaw-facing surface of the one jaw of the first and second jaws. 
     
     
       4. The surgical apparatus of  claim 2 , wherein the second heating assembly comprises a first ribbon heater. 
     
     
       5. The surgical apparatus of  claim 4 , wherein the control assembly comprises a first activation circuit that energizes the heating element and a separate second activation circuit that energizes the ribbon heater. 
     
     
       6. The surgical apparatus of  claim 5 , wherein the second heating assembly comprises a second ribbon heater and the heating element of the first heating assembly is disposed between the first ribbon heater and the second ribbon heater. 
     
     
       7. The surgical apparatus of  claim 1 , wherein the second heating assembly includes a heater actuatable by the control assembly to generate heat for resistance welding of tissue. 
     
     
       8. The surgical apparatus of  claim 7 , wherein the heater is disposed on a surface of a distal tip of the one jaw, wherein the surface of the distal tip of the one jaw constitutes a substantially different surface from the jaw-facing surface of the one jaw. 
     
     
       9. The surgical apparatus of  claim 8 , wherein the surface of the distal tip intersects substantially orthogonally with the jaw-facing surface of the one jaw and the heater comprises a ribbon heater. 
     
     
       10. The surgical apparatus of  claim 8 , wherein the surface of the distal tip intersects substantially orthogonally with the jaw-facing surface of the one jaw and the heater comprises a shaped wireform heater provided with a serpentine band pattern. 
     
     
       11. The surgical apparatus of  claim 7 , wherein the heater is disposed on an outside surface of the one jaw, wherein the outside surface of the one jaw constitutes a substantially different surface from the jaw-facing surface of the one jaw and the heater comprises a widened pad electrode configured for resistance heating. 
     
     
       12. The surgical apparatus of  claim 1 , wherein the control assembly comprises a first circuit connected to energize the first heating assembly and a second circuit connected to energize the second heating assembly, wherein the control assembly is configured to energize only one of the first heating assembly and the second heating assembly at a time. 
     
     
       13. A surgical apparatus for welding and severing tissue comprising:
 an elongated shaft; 
 a first jaw and a second jaw, wherein the second jaw is relatively movable with respect to the first jaw, wherein the first jaw and the second jaw extend from a distal end of the shaft and each of the first jaw and the second jaw comprises a jaw-facing surface; 
 a first heating assembly configured to weld tissue, sever tissue, or both weld and sever tissue, wherein the first heating assembly is a component of one jaw of the first and second jaws, and wherein the first heating assembly includes a heating element; and 
 a second heating assembly configured to spot weld tissue, wherein the second heating assembly is a component of the same jaw as the first heating assembly, and wherein the second heating assembly includes a heater actuatable by a control assembly to generate heat for resistance welding of tissue; and 
 the control assembly is operably connected to activate the first heating assembly and the second heating assembly, wherein the control assembly is operable to energize the heating element for welding tissue, or for severing tissue, or for both welding and severing tissue, and the control assembly is operable to energize the heater to generate heat for resistance welding of tissue. 
 
     
     
       14. The surgical apparatus of  claim 13 , wherein the control assembly is configured to energize only one of the first heating assembly and the second heating assembly at a time.